Electric controller



y 1955 G. J. MUCHER ELECTRIC CONTROLLER Filed April 10, 1952 miA m ELEfITRilC CDNTROLLER George 3. Marcher, Rochester, N. E, assignor to {Iiarostat Mfg. Co., Inc, Dover, N. EL, a corporation of New York Application April it), 1952, Serial No. 281,618

12 Claims. (Cl. Mill-55) This invention relates to a structurally and functionally improved control of the electrical type and aims to provide a unit of that class which will be capable of operating over a wide range of voltage and resistance values.

It is an object of the invention to furnish a mechanism which will function in an atmosphere surcharged with waste particles without any material effect on its operation. The assembly will be capable of application to and embodiment in numerous circuits and mechanisms involving a large scope of industrial and other uses.

A still further object is that of providing a mechanism which will be extremely compact and at the same time will be capable of being manufactured at a relatively low cost.

Still another object is that of designing a control involving relatively few parts, each individually simple and rugged in construction and such parts being capable of ready assemblage by comparatively unskilled labor and with use of a minimum number of tools.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating one practical embodiment of the invention and in which:

Fig. l is a front view of the control with the cover removed;

Fig. 2 is a transverse sectional view taken along the line 22 and in the direction of the arrows as indicated in Fig. 1;

Fig. 3 is a sectional plan view taken along the line 33 and in the direction of the arrows as indicated in Fig. 2;

Fig. 4 is a perspective view of the main portions of the rotor assembly and showing them in separated condition; and

Fig. 5 is a rear face view with part of the cover broken away and certain of the mechanism removed.

In these views, the numeral 5 indicates the casing of the device preferably formed of a suitable dielectric material and embracing a cup shape. The base of this casing is formed with a central opening defined by a bushing 6 extending beyond the base of the casing. Adjacent the inner face of that base and extending along the side walls of the casing are rest portions 7. Terminal shields 3 extend outwardly from the side wall of the casing at spaced points and are also preferably integral therewith. intervening these shields and extending from the inner face of the casing is a protuberance 9. Projecting upwardly from the cup base are any desirable number of circular ridges it) concentrically disposed with respect to each other. These ridges serve as voltage traps to prevent leakage of current. The shields 8 prevent leakage of current at points adjacent the terminals.

A resistance 11 in the form of a strip or otherwise is applied to the inner face of the cup and bears against the rest portions 7. The ends of this strip lie adjacent the side edges of the protuberance 9 which thus serves as a positioning element therefor. Anchoring units conveniently in the form of rivets 12 extend through the strip at points adjacent its ends and into the bafiles provided g gwv Patented July 5, 1955 by shields 8. These securing elements mount terminals 13 to which current-conducting leads (not shown) are connected. As afore indicated the resistance 11 may embrace any desired and proper physical characteristics. Under normal conditions, it will remain against any probability of displacement with respect to other parts of the assembly. it is apparent that if any positioning and anchoring expedients additional to, or in substitution of those shown are desirable, they may be resorted to.

The cover completes the stationary assembly. This cover is conveniently in the form of a plate 14 of dielectric material and having a diameter such that it may rest on the inner ledge portion defining the edge of the cup of easing 5'. Plate M is provided with recesses 24' through which the terminals 13 may extend. A pin 15 may project from the rim of the cup and be integral therewith. Cover plate 14 is provided with a notch portion 15 through which this extension or pin passes. Any suitable securing element 16 may be applied to the pin beyond the cover and thus serve to retain the latter in position. The side edges of the recesses in the cover extend into notches 17 of the terminals 13 as the cover is slid into position. With the cover in such position, it may be rocked so that the pin extension 15 passes between the legs of the notch portion 15 and the securing element 16 is applied. By virtue of the latter and the outer portions defining the notches 17, the cover is prevented from being axially displaced.

The cover supports a collector member or ring of any desired shape. In the embodiment under consideration, this ring takes the form of a disk or plate 18 of metal. Integral with the plate is an extension 1% which projects through an opening in the cover. Likewise integral with the plate is a terminal 29 presenting enlarged and reduced portions and cooperating with a cover opening 21 of a keyhole type so as to include a reduced portion. Accordingly the extended portions of the terminal may be passed through the cover and bear against the outer face of the same to secure the collector ring in position. It is apparent that other forms of collector ring and mounting methods for the same might be resorted to, but it is preferred, that in accordance with the present teachings, the assembly of the control include structure generally along the type just described.

Bushing a; rotatably supports shaft 22 which con venicntly is prevented from inward displacement by being provided with a groove receiving a retaining ring 23 bearing against the bushing. The inner end 24 or the shaft is reduced and of non-circular configuration. it receives a contact carrier embracing a non-conductive plate 25 which is furnished with a central opening 26 for the shaft end. This plate is conveniently provided with positioning openings in the form of notches at diametrically opposite points in its edgzs. These notches accommodate the ends and of a member 36 provided with an opening 31 through which the shaft also extends and beyond which it may be headed. This member overlies carrier 25 and has its arms and passing through the notches or other openings 27. if it is desired to incorporate a step function in this part, the arm 28 may be relatively long to extend beyond the rear face of the plate. After these units are mounted and the shaft extended through bushing 6, plate 25 will bear against the innermost ridge it This will prevent an outward displacement of shaft 22 and the parts carried thereby.

The contact unit preferably includes a metallic body or strip 32, the ends of which are extended rearwardly as indicated at 33. Portions of the strip 32 are extended outwardly as indicated at 3 1 to provide collector ring arms. Extending tangentially from one of the rearward portions 33 are any desirable number of wipers or contact arms 35. It is of course to be understood that the metal of which the contact strip 32 is formed embodies adequate resiliency so that parts 3 and 35 will yieldingly extend in the directions stated. The rearwardly extending portions 33 are provided with notches 3d beyond which enlarged portions 37 are disposed. The ends of strip 32 terminate in reduced, inwardly extending tip portions 38 providing detents.

A shield 39 of non-conductive material is formed with openings at! of keyhole configuration. The major areas of these openings (which extend inwardly) present a width such that portions 36, 37 and 38 of the rearward extensions may pass therethrough. However, their width is not sumcient to permit a passage of the base portions of the rearward extensions 33. Gbviously the openings might embody any desired outline providing sufficient area for the passage of the extensions of the contact unit up to the base portions of the extensions and interlocking cooperation with the edges of notches 36. The length of the extensions is such that they may pass through the openings 40 in shield 39 and extend into and beyond notches 41 in shield or carrier plate 25. These notches as shown are conveniently spaced 90 from the notches 27. As will be apparent, both shields Z5 and 39 serve in addition to their other functions, as voltage traps to prevent a leakage of current. The rotation of this assembly may be limited in any desired manner such as having the longer arm 28 of the stop member 30 traversing the space between the ridges 1i) and engaging with an arresting abutment 42 which is preferably formed integrally with the casing 5.

In assembling a mechanism of this type, the usual procedure will be as follows: the contact carrying shield 25 will be applied to the reduced end portion 24 of shaft 22. Thereupon, member 30 will be applied to that shaft end and the latter will be headed over as shown to secure the parts against displacement. In positioning member 39, it will be remembered that extensions 23 and 29 of the same are extended through the notches 27. Shaft 22 may now be threaded through bushing 6 and the retaining ring 23 or other anchoring expedient applied to the parts. The casing 5 will have been assembled with the resistance which will be anchored in position. The cover 14 will have the collector ring applied thereto and thus secured against movement.

The person assembling the parts will now exert pressure against and pass the reawardly extending portions 33 of strip 32 through the keyhole openings 40. When the notches 36 are in line with the shield 39, the tension exerted on portions 33 during this shifting of the parts will be released. Accordingly, the edges of the notches will move into the base portions of the openings 40. Under these circumstances, the enlarged parts 37 will ride against one face of shield 39 and the base parts of the inward extension 33 will ride against the opposite face of that shield. In this manner, the contact unit together with the shield in effect becomes one unit. Therefore, if that unit is moved rearwardly towards the plate 25, then the inwardly extending portions 38 acting as detents Will ride in contact with the edges of notches 411 and beyond the same. This movement will continue until the enlarged portions 37 bear against what might be termed the outer face of the contact carrier 25. Therenpon, the contact unit together with the integral resistance wipers and collector ring arms will be fixed with respect to the rotor.

Accordingly, if shaft 22 is turned with respect to casing 5, contact strip 32 will be moved in synchronism therewith. With the parts thus disposed, the cover 14 may be applied to the casing in the manner aforedescribed. With the application of the securing element 16 to the pin 15 the assembly is completed. It is to be emphasized that in accordance with the terminology of this art element 18 is referred to as a ring. Actually, as shown, it embraces a disk and could include other outlines. Also, the openings referred to as having a key- 4 hole outline need only include a portion.

Thus among others the several objects of the invention as specifically aforenoted are achieved. It is obvious that numerous changes in construction and rearrangement of the parts may be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

1. In a control a cover for a casing, said cover being formed with a keyhole opening and a second opening spaced from said keyhole opening, a collector ring applied to the inner face of said cover, an extension forming a part of said ring and projecting into said second opening, a terminal also extending from said ring and passing through said keyhole opening and said terminal being formed with notches at a point short of its end to interlock with the surfaces of said cover adjacent said keyhole opening to removably retain said collector ring in position.

2. In a control in combination a shield plate formed with keyhole openings, a strip, contact arms extending from said strip, rearwardly extending portions integral with said strip, reduced parts embraced in said portions and to receive parts of said shield adjacent said openings and detent parts integral with said rearwardly extending portions and disposed adjacent the ends of the same.

3. in a control in combination a shield plate formed with keyhole openings, a contact strip, rearwardly extending portions integral with said strip, reduced parts embraced in said portions and to receive parts of said shield adjacent said openings, detent parts integral with said rearwardly extending portions and disposed adjacent the ends of the same, a second shield presenting edges, said detents cooperating with said edges to retain said firstnarned shield and said strip against displacement and the length of said rearwardly extending portions being such that said shields are maintained in spaced relationship.

4. in an eiectrical control in combination a contact carrier formed with a pair of openings, at least one of said openings having a keyhole outline, an electrically conductive member, a pair of extensions forming a part of said member and passing one into each of said openings, an enlarged part embraced in one or" said extensions and of a width such that it passes solely through the enlarged area of the opening having the keyhole outline and said one extension being of reduced width at a point short of said enlarged part; the edges of the extension in line with the area of reduced width being engageable with the edges defining the constricted zone of said keyhole opening to releaseably secure said member to said contact carrier.

5. As an article of manufacture a collector member for use in an electrical control, said member comprising a body to be disposed adjacent a portion of a casing forming a part of said control, a pair of supporting extensions forming a part of said body, one of said extensions being flexible and embracing a portion to pass through and be retained within the area of an opening formed in the casing and a latching part integral with said portions and shiftable-under a flexing of said one extension-to engage the face of the casing to detachably secure said ring to said casing portion.

6. In an electrical control a rotor assembly including in combination a mounting plate, a contact unit, said plate providing a transversely extending edge portion, flexible projecting portions extending from said unit in a direction substantially perpendicular to the same and to the surface of said plate, a detent forming a part of one projecting portion adjacent the end of the same for sliding contact with the edge portion and latching engagement with said plate to releaseably retain said unit against movement with respect to said plate, a shield presenting edges to be engaged by said portions and means forming a part of said projecting portions to maintain said shield in a position interposed between and spaced from said plate and unit.

7. In an electrical control in combination an electrirestricted or retaining cally conductive member, a mounting member, one of said members presenting an opening having a keyhole outline, a flexible arm portion extending from the second of said members, a relatively enlarged part embraced in said arm and defining adjacent it a recessed area in the latter and the maximum width of said opening being such that the enlarged arm part will pass therethrough; the arm being thereafter laterally movable in a direction such that the edges of its recessed area engage with the surfaces adjacent those defining the reduced portion of said opening whereby to releaseably secure said members against separation.

8. In an electrical control a rotor assembly including in combination a contact carrier comprising a plate formed with an opening, a shield likewise formed with an opening, said shield opening including an area of reduced size in comparison With the remainder of such opening area, an electrically conducting strip, an angularly extending portion forming a part of said strip and having a notch in its side edge, said portion extending through said shield and plate openings with its notch lying within the area of reduced size and said shield opening and means for detachably securing the end of said angular portion to said plate.

9. In an electrical control a rotor assembly including in combination a contact carrier comprising a plate formed with an opening, a shield likewise formed with an opening, said shield opening including an area of reduced size in comparison with the remainder of such opening area, an electrically conducting strip, an angularly extending portion forming a part of said strip and having a notch in its side edge, said portion extending through said shield and plate openings with its notch lying within the area of reduced size and said shield opening and said plate opening engaging said angular portion to maintain the notch of the latter in such position.

10. In an electrical control a rotor assembly including in combination a contact carrier comprising a plate formed with an opening, a shield likewise formed with an opening, said shield opening including an area of reduced size in comparison with the remainder of such opening area, an electrically conducting strip, an angularly extending portion forming a part of said strip and having a notch in its side edge, said portion extending through said shield and plate openings with its notch lying within the area of reduced size and said shield opening, said plate opening engaging said angular portion to maintain the notch of the latter in such position and a detent part adjacent the end of said angular portion to provide a detachable connection between the same and surfaces of said plate.

11. In an electrical control in combination a rotor comprising a plate, means whereby said plate is attachable to a control shaft, said plate being formed with a pair of openings at substantially diametrically opposite points in its body, a contact element, angularly projecting portions extending from said element, detent means forming parts of such portions for detachably coupling said element with said plate and a contact arm extending from said element to be engageable with an electrically conducting member of a control as said rotor is shifted.

12. In an electrical control in combination a rotor comprising a plate, means whereby said plate is attachable to a control shaft, said plate being formed with a pair of openings at substantially diametrically opposite points in its body, a contact element, angularly projecting portions extending from said element, detent means forming parts of such portions for detachably coupling said element with said plate, a contact arm extending outwardly from the face of said element and a second contact arm projecting laterally from one of said angularly projecting portions.

References Cited in the file of this patent UNITED STATES PATENTS 2,213,078 Stoekle Aug. 27, 1940 2,255,132 Stoekle Sept. 9, 1941 2,289,115 Hadley July 7, 1942 

